Having regular lie-ins is worse for the body than getting too little sleep, new research suggests.
Scientists have known for some time that not getting enough sleep increases the risk of a string of health complaints such as high blood pressure, heart disease, obesity and diabetes.
But a new review led by Keele University in Staffordshire, England, found that people who slept for an average of 10 hours a night were 30pc more likely to die early than those who only slept for seven hours.
Current recommendations suggest that adults should sleep for eight hours a night and although the precise benefits of sleep are still unknown, experts believe it gives the body a chance to repair cells and blood vessels, clear out waste and boost the immune system.
However, it was generally thought that too little sleep was far worse than too much. But the new review of 74 studies involving three million people shows the opposite is true.
The research found that people with a sleep duration of 10 hours were 56pc more likely to suffer a stroke, at 49pc increased risk of dying from cardiovascular disease and a 44pc increase in coronary heart disease.
The results show that sleeping for longer than the recommended duration of seven or eight hours may be associated with a moderate degree of harm, compared to those who sleep for shorter durations.
It is unclear why oversleeping is bad for health. Some studies have suggested that it changes the production of brain chemicals such as serotonin or dopamine which can lead to depression. Lying in the same position for too long can also weaken muscles.